Telephone system.



no MODELNN T. PAUL. TELEPHONE SYSTEM.

APPLIOATION FILED JUNE 14, 1901.

PATENTED APR. 14, 1903;

2 SHEETS-SHEET 1- O N k I mmuq INVENTOH m 15mm; ffizaz No. 725,476. I PATENTED APR. 14, 1903.

T. PAUL.

' TELEPHONE SYSTEM.

APPLICATION FILED JUNE 14, 1901.

N0 HEEL); 2 SHEETS-SHEET 2.

IN VENTUI? Tim/Mad Paul M Arm 8 UNIT D STATES.

THOMAS PAUL, or

PATENT OFFI EQ YORKTON, CANADA, Assienoaor ONE-HALF TO JOHN L. MoDOUGAL, or YORKTON, CANADA- TELEPHONE SYSTEM.

srncrrxcarron'form n part of Letters Patent No. 725,476, dated April 14,1903.

' hpplication filed June 14,1901. Serial No. 64.542. (No as.)

To all whom it may concern: Be itknown that I, THOMAS PAUL, asubject of the King'of Great Britain, and aresident f Yorkton, in" the North -West Territories,

Dominion of Canada, have invented a new and I advantages of such a system lie in the fact that there are no' annunciator-coils or relay-coils in series with the talking-circuit, which in some of the systemsnow patented greatly impede the voice-currents. Neither are there any annunciator-coi'ls in shunt with the telephone-circuit which allow of leakage of the voice-currents between the lines.

In the system described either a metallic or ground return maybe used for the signaling-circuit and but one strand of wire is required for the plug connections at the central station. Another peculiar advantage of this system is due to the fact-that but one springcontact is required in the jack for making connections. This obviates the shortcircuiting arising from dust or other particles lighting in the jack-sockets and being pushed through and between the jack-springs.

By the arrangement hereinafter set forth the ringing up of the subscribers is"accon1- plished with great ease by the operator and telephonic connections are rapidly made. This increases the number of subscribers that a single operator can handle. A. great commercial advantage is derived by the use of simple and well-known instruments, which provides for a ready installation of the system.

Further objects and improvements will appear in the description of myinvention.

Reference is to be had to the accompanying drawings,forming apart of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 illustrates the connection existing between a subscribers station and the central station. Fig. 2 illustrates the connections that exist when two subscribers areconnected together. Fig. 3 illustrates the connections between two subscribers and also the connections with the operator at the cention-coil I.

m1 station; andFig. 4: illustrates the same 1 S indicates the well-known telephone switchhook, and T and L indicate, respectively, the welleknown' formsof telephone-transmitter and local battery, the saidtransmitter and battery. being connected in series with the primary I of the induction-coil and the circuit closed automatically by the telephone switch-hook when the receiver is removed therefrom. 1 v 1 B indicates the well-knownsignaling in strument, connected to the normal contact 71.,

by means of the common return signalingwire G, while the talking-circuit is'completed through the telephone-receiver and the secondary of the induction coilby means of the lines I and l.

The line Z, leading from each of. the sub scribers stations, isconnected to a spring M,-

a series of which are in contact with :ame-

tallic strip D. For'the purpose of clearly setting forth this system "but one of these.

metallic-strips isillustrated. This metallic strip is locatedbehind the panel of a switchboard W and in line with sockets s, which i with the spring M'and lifts it from contact with the'metallic strip D, therebybreaking connection betweenthe said spring and the metallic strip. The operators telephone set is connected with the metallic strip D. Also connected with this metallic strip Dis a me- .tallic contact E, which is connected by a wire vX with the common signaling-wire G. In "proximity-to the metallic contact E is ametalliccontact O, which is connected to the signaling-battery U. This battery is connected by two branches, one through an annunciator or indicator I and the other through a second signaling-battery V, which is in turn connected to the common signaling-wire G. r r

The operators set consists of the usual instruments-namely, the primary and secondary induction-coils, transmitter, and talkingbattery indicated by the letters I,I ,T,and L, respectively. The receiver of the operator is illustrated as connected in parallel with the secondary of the induction-coil in the same manner as illustrated at the subscribers station. This connection, however, may be changed without departing from the spirit of my invention by connecting the telephone-receiver in series with the secondary of the induction-coil.

\Vhen connection is desired by any of the subscribers, the operator inserts the plug P in the jack of the called-for subscriber, and when response is made by the said subscriber the operator inserts the plug P in the jack of the calling subscriber, thereby making a complete metallic circuit, as illustrated in Fig. 2. The talking-circuit passes from the secondary of the induction-coil at one station to the switch-hook S, line I, spring-contact M, plug P, strand Q, plug P, spring-contact M, line Z, switch-hook S at the other subscribers station, receiverR, hack to the first subscriber byway of the line I. It is to be understood that all of the lines Z of a section of the system are normally connected together through X with the pivoted end of the telephone-switch S at the central station. \Vhen the called subscriber has been connected in the manner shown in Fig. 2 and has completed conversationwith the calling subscriber and the calling subscriber wishes to call up a second subscriber,

it may be accomplished by the connections illustrated in Fig. 3. The subscriber, say No. 68, who was formerly called up having replaced his receiver on the switch-hook located at his station closes the connection between the said switch-hook and the signaling-line G, which isiu turn connected through X with the telephone-receiver of the central station. The circuit is completed by means of the telephone switch-hook S, located at the central station,which is in turn connected with the station of the calling subscriber, say No. 37, who wishes to continue conversation with another subscriber by means of the liueZ. Thislast-namedsubscribercan theninstruct the operator at the central station of the desired third subscriber with Whom he wishes to talk, andthe operator will then make the necessary connections by means of plugswitching connection.

The operation of myimproved system is as follows: When subscriber No. 37, for .purpose of illustration, wishes to make connection with subscriber No. Q8, he lifts his receiver from the switch-hook, which closes the connection with the said switch-hook and the abnormal contacts at his station, closing the circuit through the receiver and the secondary I of the induction-coil in parallel to the line Z, the switch S, located at the central station, then to the normal contact at, as illustrated in Fig. 4, through the-bell or other indicator I, to the battery V, the connection X, the metallic strip D, the spring-contact M,- and back to the subscribers station and switch S by the line I. This causes the operation of the indicating device or the annunciator -drop I. The operator in response thereto lifts the receiver from the hook and closes the talking-circuit with the calling will indicate the. particular subscriber that is calling, and the only information that the operator will need to receive willbe the number of the subscriber with which the said subscriber wishes to converse. Upon receiving the desired information the operator inserts the plug P in the socket of the called-for subscriber and makes connection thereby with the metallic spring M and the linel leading to the said subscriber. He then with the other plug P makes contact with the metallic contact 0 and then draws it across to the metallic contact E. By this operation he has first caused a signaling-current to pass over-the signaling-line G, through the bell B and the switch-hook S, which is at station 68, in contact with the normal contact a, thereby causing the bell B to ring. By this connection the batteries U and V are thrown into series with the bell B, which is sufficient to cause the operation of the bell'located at the subscribers station. Upon drawing the plug across to the contact E and removing the receiver from the switch-hook the operator closes the central-station end of a talkingcircuit between herself and the called-for subscriber by means of the springcontact M, the plug P, strand Q plug P, metallic contact E, line X, induction-coil 1", receiver R, switch-hook S, and line Z,through the subscribers talking instruments. circuit connection will then indicate to the operator at the central station when the called-forsubscriber has removed his receiver from the hook and is ready to converse. The operator will then insert the plug P which was used for calling the called-forsubscriber This ' into the jack of the calling subscriber, and

. nection X by way of line Z, through the receiver R, switch S, contact-spring M, plug P, strand Q, plug P, contact-spring'M, and switch S of-the first subscriber. This causes the operation of the indicator or annunciator I and indicates to the operator at the central station that conversation has been completed. The operator will then withdraw the plugs from the sockets and the normal conditions will exist.

It is to be understood than once a thorough connection has been made between subscribers the withdrawal of one or both of the connecting-plugs before conversation. has been completed cannot occur without the operator at the centralstation being made aware of such mistake. Either the indicator-shutter will fall when the switch at the centralstation is normal or the subscribersconversation will be overheard by the operator.

Having thus described my invention, I claim as new and desire to secure by Letters Patent I V 1. In a telephone system, the combination: of a subscribers station and a pair of telephone-lines leading thereto, one of said lines being connected to a switch at the'central station, a normal contact for said switch, a pair of abnormal contactsfor said switch, atelephone-receiver connected with'one of said abnormal contacts, and with any of said telephone -lines, a transmitter, a local battery and a primary coilconnected serially together and to both of said abnormal contacts, and a secondary coil energiaed by induction from said primary coil and connected with one of said telephone-lines, a metallic strip, a spring normally in contactwith said strip, said receiver being connected in series with said metallic strip and spring, another switch located at a different subscribers station and provided with anormal contact, and metallic connections controllable at will from the central station for temporarily establishing a talking-circuit from the central station to said first-mentioned subscribers station through said normal contact of'said second-mentioned subscribers station.

2. In a telephone system, a number of'subscribers stations, a central station, lines arranged-in pairs connecting said subscribers" stations with the central station and also connecting one of said subscribers stations directly with another, a separate line connecting each of said subscribers stations with the central station, means controllable'at will and disposed at said central station for openingand closing each of said separate 11m.

and. for temporarily connecting said separate lines together, switch-hooks at all'of saidsta= I tions,-provided with normal and abnormal contacts, the arrangementbeing such that a talking-circuit may be formed between "the central station and a 'subscribe1"s'stationthrough the abnormal contact of one of said subscribers stations, the abnormal contact of said central station, and the normal contact of another of said subscribers stations.

In testimony whereof I have-signed my name to this specification in the presence of two subscribingwitnesses. 7

' v THOMAS PAUL.

Witnesses:

J AMES F. MA LEARY, CLAwsoN FEASS. 

